kernel/linux.git/Documentation/driver-api, branch v6.1.178

PCI: Move Resizable BAR code to rebar.c

2026-07-24T13:55:13+00:00

[ Upstream commit 9f71938cd77f32a448f40a288e409eca60e55486 ] For lack of a better place to put it, Resizable BAR code has been placed inside pci.c and setup-res.c that do not use it for anything. Upcoming changes are going to add more Resizable BAR related functions, increasing the code size. As pci.c is huge as is, move the Resizable BAR related code and the BAR resize code from setup-res.c to rebar.c. Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Christian König Link: https://patch.msgid.link/20251113180053.27944-2-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nvdimm/btt: Handle preemption in BTT lane acquisition

2026-07-24T13:54:38+00:00

[ Upstream commit 8d4b989d9c9afe5f185aa5853b666fc4617afe9e ] BTT lanes serialize access to per-lane metadata and workspace state during BTT I/O. The btt-check unit test reports data mismatches during BTT writes due to a race in lane acquisition that can lead to silent data corruption. The existing lane model uses a spinlock together with a per-CPU recursion count. That recursion model stopped being valid after BTT lanes became preemptible: another task can run on the same CPU, observe a non-zero recursion count, bypass locking, and use the same lane concurrently. BTT lanes are also held across arena_write_bytes() calls. That path reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush(). Some provider flush callbacks can sleep, making a spinlock the wrong primitive for the lane lifetime. Replace the spinlock-based recursion model with a dynamically allocated per-lane mutex array and take the lane lock unconditionally. Add might_sleep() to catch any future atomic-context caller. Found with the ndctl unit test btt-check.sh. Fixes: 36c75ce3bd29 ("nd_btt: Make BTT lanes preemptible") Assisted-by: Claude-Sonnet:4.5 Tested-by: Aboorva Devarajan Reviewed-by: Aboorva Devarajan Reviewed-by: Vishal Verma Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20260528021625.618462-1-alison.schofield@intel.com Signed-off-by: Alison Schofield Signed-off-by: Sasha Levin

tty: fix tty_port_tty_*hangup() kernel-doc

2026-01-11T14:19:26+00:00

commit 6241b49540a65a6d5274fa938fd3eb4cbfe2e076 upstream. The commit below added a new helper, but omitted to move (and add) the corressponding kernel-doc. Do it now. Signed-off-by: "Jiri Slaby (SUSE)" Fixes: 2b5eac0f8c6e ("tty: introduce and use tty_port_tty_vhangup() helper") Link: https://lore.kernel.org/all/b23d566c-09dc-7374-cc87-0ad4660e8b2e@linux.intel.com/ Reported-by: Ilpo Järvinen Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20250624080641.509959-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

2025-06-04T12:40:13+00:00

[ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ] The following splat has been observed on a SAMA5D27 platform using atmel_serial: BUG: sleeping function called from invalid context at kernel/irq/manage.c:738 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0 preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<00000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec softirqs last enabled at (0): [] copy_process+0x1ca0/0x7bec softirqs last disabled at (0): [<00000000>] 0x0 CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74 Hardware name: Atmel SAMA5 Workqueue: hci0 hci_power_on [bluetooth] Call trace: unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x44/0x70 dump_stack_lvl from __might_resched+0x38c/0x598 __might_resched from disable_irq+0x1c/0x48 disable_irq from mctrl_gpio_disable_ms+0x74/0xc0 mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4 atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8 atmel_set_termios from uart_change_line_settings+0x15c/0x994 uart_change_line_settings from uart_set_termios+0x2b0/0x668 uart_set_termios from tty_set_termios+0x600/0x8ec tty_set_termios from ttyport_set_flow_control+0x188/0x1e0 ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc] wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth] hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth] hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth] hci_power_on [bluetooth] from process_one_work+0x998/0x1a38 process_one_work from worker_thread+0x6e0/0xfb4 worker_thread from kthread+0x3d4/0x484 kthread from ret_from_fork+0x14/0x28 This warning is emitted when trying to toggle, at the highest level, some flow control (with serdev_device_set_flow_control) in a device driver. At the lowest level, the atmel_serial driver is using serial_mctrl_gpio lib to enable/disable the corresponding IRQs accordingly. The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to disable_irq (called in mctrl_gpio_disable_ms) being possibly called in some atomic context (some tty drivers perform modem lines configuration in regions protected by port lock). Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one and a blocking one. Replace mctrl_gpio_disable_ms calls with the relevant version depending on whether the call is protected by some port lock. Suggested-by: Jiri Slaby Signed-off-by: Alexis Lothoré Acked-by: Richard Genoud Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

fpga: manager: add owner module and take its refcount

2024-12-14T18:53:12+00:00

[ Upstream commit 4d4d2d4346857bf778fafaa97d6f76bb1663e3c9 ] The current implementation of the fpga manager assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the manager if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_manager struct and use it to take the module's refcount. Modify the functions for registering the manager to take an additional owner module parameter and rename them to avoid conflicts. Use the old function names for helper macros that automatically set the module that registers the manager as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a manager without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga manager. Other changes: opportunistically move put_device() from __fpga_mgr_get() to fpga_mgr_get() and of_fpga_mgr_get() to improve code clarity since the manager device is taken in these functions. Fixes: 654ba4cc0f3e ("fpga manager: ensure lifetime with of_fpga_mgr_get") Suggested-by: Greg Kroah-Hartman Suggested-by: Xu Yilun Signed-off-by: Marco Pagani Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20240305192926.84886-1-marpagan@redhat.com Signed-off-by: Xu Yilun Signed-off-by: Sasha Levin Signed-off-by: Xiangyu Chen Signed-off-by: Sasha Levin

fpga: bridge: add owner module and take its refcount

2024-12-14T18:53:12+00:00

[ Upstream commit 1da11f822042eb6ef4b6064dc048f157a7852529 ] The current implementation of the fpga bridge assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the bridge if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_bridge struct and use it to take the module's refcount. Modify the function for registering a bridge to take an additional owner module parameter and rename it to avoid conflicts. Use the old function name for a helper macro that automatically sets the module that registers the bridge as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a bridge without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga bridge. Other changes: opportunistically move put_device() from __fpga_bridge_get() to fpga_bridge_get() and of_fpga_bridge_get() to improve code clarity since the bridge device is taken in these functions. Fixes: 21aeda950c5f ("fpga: add fpga bridge framework") Suggested-by: Greg Kroah-Hartman Suggested-by: Xu Yilun Reviewed-by: Russ Weight Signed-off-by: Marco Pagani Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20240322171839.233864-1-marpagan@redhat.com Signed-off-by: Xu Yilun Signed-off-by: Sasha Levin Signed-off-by: Xiangyu Chen Signed-off-by: Sasha Levin

ipmi: docs: don't advertise deprecated sysfs entries

2024-10-17T13:20:54+00:00

[ Upstream commit 64dce81f8c373c681e62d5ffe0397c45a35d48a2 ] "i2c-adapter" class entries are deprecated since 2009. Switch to the proper location. Reported-by: Heiner Kallweit Closes: https://lore.kernel.org/r/80c4a898-5867-4162-ac85-bdf7c7c68746@gmail.com Fixes: 259307074bfc ("ipmi: Add SMBus interface driver (SSIF)") Signed-off-by: Wolfram Sang Message-Id: <20240901090211.3797-2-wsa+renesas@sang-engineering.com> Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

fpga: region: add owner module and take its refcount

2024-06-12T09:03:39+00:00

[ Upstream commit b7c0e1ecee403a43abc89eb3e75672b01ff2ece9 ] The current implementation of the fpga region assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the region during programming if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_region struct and use it to take the module's refcount. Modify the functions for registering a region to take an additional owner module parameter and rename them to avoid conflicts. Use the old function names for helper macros that automatically set the module that registers the region as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a region without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga region. Fixes: 0fa20cdfcc1f ("fpga: fpga-region: device tree control for FPGA") Suggested-by: Greg Kroah-Hartman Suggested-by: Xu Yilun Reviewed-by: Russ Weight Signed-off-by: Marco Pagani Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20240419083601.77403-1-marpagan@redhat.com Signed-off-by: Xu Yilun Signed-off-by: Sasha Levin

PCI/P2PDMA: Remove reference to pci_p2pdma_map_sg()

2024-01-25T23:27:44+00:00

commit 9a000a72af75886e5de13f4edef7f0d788622e7d upstream. Update Documentation/driver-api/pci/p2pdma.rst doc and remove references to obsolete p2pdma mapping functions. Fixes: 0d06132fc84b ("PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg()") Link: https://lore.kernel.org/r/20231113180325.444692-1-tstruk@gmail.com Signed-off-by: Tadeusz Struk Signed-off-by: Bjorn Helgaas Reviewed-by: Logan Gunthorpe Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

spi: Update reference to struct spi_controller

2022-12-31T12:32:06+00:00

[ Upstream commit bf585ccee22faf469d82727cf375868105b362f7 ] struct spi_master has been renamed to struct spi_controller. Update the reference in spi.rst to make it clickable again. Fixes: 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"") Signed-off-by: Jonathan Neuschäfer Link: https://lore.kernel.org/r/20221101173252.1069294-1-j.neuschaefer@gmx.net Signed-off-by: Mark Brown Signed-off-by: Sasha Levin